I'm no fashion expert; HELP!!!

So, Sunday saw me go suit shopping for an upcoming 21st birthday party in Essex.

What started out as a farce, ended up being extremely productive (as the photo probably tells you)

The middle dark grey suit was purchased first, even though my intention was to go out and buy only a waistcoat to go with either of my grey trousers.

However, after searching the River Island clearance rail, I found 2 waistcoats (seen above) which are slightly too big, but wearable and for £10 each, I thought why not?! Then there was the dilemma as to which one would go with my already owned grey trousers. Luckily however, I found a matching pair of trousers for the light grey waistcoat (seen on the left) also in the sale. The waistcoat on the right is with the same pair of trousers.

Personally I prefer the option on the right (darker waistcoat with lighter trousers) but then again, I know nothing about trends and fashion and what looks cool/ decent. (FYI. The suit in the middle is definitely going back - so it's between the two waistcoats).

So, the choice is yours! Feel free to throw your opinion in there!